4.4BSD/usr/src/sys/miscfs/kernfs/kernfs_vnops.c
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kernfs_vnops.c 8.1 (Berkeley) 6/10/93
*/
/*
* Kernel parameter filesystem (/kern)
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/vmmeter.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/buf.h>
#include <sys/dirent.h>
#include <miscfs/kernfs/kernfs.h>
#define KSTRING 256 /* Largest I/O available via this filesystem */
#define UIO_MX 32
#define READ_MODE (S_IRUSR|S_IRGRP|S_IROTH)
#define WRITE_MODE (S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)
#define DIR_MODE (S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
struct kern_target {
char *kt_name;
void *kt_data;
#define KTT_NULL 1
#define KTT_TIME 5
#define KTT_INT 17
#define KTT_STRING 31
#define KTT_HOSTNAME 47
#define KTT_AVENRUN 53
int kt_tag;
int kt_rw;
int kt_vtype;
} kern_targets[] = {
/* NOTE: The name must be less than UIO_MX-16 chars in length */
/* name data tag ro/rw */
{ ".", 0, KTT_NULL, VREAD, VDIR },
{ "..", 0, KTT_NULL, VREAD, VDIR },
{ "boottime", &boottime.tv_sec, KTT_INT, VREAD, VREG },
{ "copyright", copyright, KTT_STRING, VREAD, VREG },
{ "hostname", 0, KTT_HOSTNAME, VREAD|VWRITE, VREG },
{ "hz", &hz, KTT_INT, VREAD, VREG },
{ "loadavg", 0, KTT_AVENRUN, VREAD, VREG },
{ "pagesize", &cnt.v_page_size, KTT_INT, VREAD, VREG },
{ "physmem", &physmem, KTT_INT, VREAD, VREG },
#if 0
{ "root", 0, KTT_NULL, VREAD, VDIR },
#endif
{ "rootdev", 0, KTT_NULL, VREAD, VBLK },
{ "rrootdev", 0, KTT_NULL, VREAD, VCHR },
{ "time", 0, KTT_TIME, VREAD, VREG },
{ "version", version, KTT_STRING, VREAD, VREG },
};
static int nkern_targets = sizeof(kern_targets) / sizeof(kern_targets[0]);
static int
kernfs_xread(kt, buf, len, lenp)
struct kern_target *kt;
char *buf;
int len;
int *lenp;
{
int xlen;
switch (kt->kt_tag) {
case KTT_TIME: {
struct timeval tv;
microtime(&tv);
sprintf(buf, "%d %d\n", tv.tv_sec, tv.tv_usec);
break;
}
case KTT_INT: {
int *ip = kt->kt_data;
sprintf(buf, "%d\n", *ip);
break;
}
case KTT_STRING: {
char *cp = kt->kt_data;
int xlen = strlen(cp) + 1;
if (xlen >= len)
return (EINVAL);
bcopy(cp, buf, xlen);
break;
}
case KTT_HOSTNAME: {
char *cp = hostname;
int xlen = hostnamelen;
if (xlen >= (len-2))
return (EINVAL);
bcopy(cp, buf, xlen);
buf[xlen] = '\n';
buf[xlen+1] = '\0';
break;
}
case KTT_AVENRUN:
sprintf(buf, "%ld %ld %ld %ld\n",
averunnable.ldavg[0],
averunnable.ldavg[1],
averunnable.ldavg[2],
averunnable.fscale);
break;
default:
return (EINVAL);
}
*lenp = strlen(buf);
return (0);
}
static int
kernfs_xwrite(kt, buf, len)
struct kern_target *kt;
char *buf;
int len;
{
switch (kt->kt_tag) {
case KTT_HOSTNAME: {
if (buf[len-1] == '\n')
--len;
bcopy(buf, hostname, len);
hostname[len] = '\0';
hostnamelen = len;
return (0);
}
default:
return (EIO);
}
}
/*
* vp is the current namei directory
* ndp is the name to locate in that directory...
*/
kernfs_lookup(ap)
struct vop_lookup_args /* {
struct vnode * a_dvp;
struct vnode ** a_vpp;
struct componentname * a_cnp;
} */ *ap;
{
struct vnode **vpp = ap->a_vpp;
struct vnode *dvp = ap->a_dvp;
struct componentname *cnp = ap->a_cnp;
char *pname;
struct proc *p;
int error;
struct vnode *fvp;
int i;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_lookup(%x)\n", ap);
printf("kernfs_lookup(dp = %x, vpp = %x, cnp = %x)\n", dvp, vpp, ap->a_cnp);
#endif
pname = cnp->cn_nameptr;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_lookup(%s)\n", pname);
#endif
if (cnp->cn_namelen == 1 && *pname == '.') {
*vpp = dvp;
VREF(dvp);
/*VOP_LOCK(dvp);*/
return (0);
}
#if 0
if (cnp->cn_namelen == 4 && bcmp(pname, "root", 4) == 0) {
*vpp = rootdir;
VREF(rootdir);
VOP_LOCK(rootdir);
return (0);
}
#endif
/*
* /kern/rootdev is the root device
*/
if (cnp->cn_namelen == 7 && bcmp(pname, "rootdev", 7) == 0) {
*vpp = rootvp;
VREF(rootvp);
VOP_LOCK(rootvp);
return (0);
}
/*
* /kern/rrootdev is the raw root device
*/
if (cnp->cn_namelen == 8 && bcmp(pname, "rrootdev", 8) == 0) {
if (rrootvp) {
*vpp = rrootvp;
VREF(rrootvp);
VOP_LOCK(rrootvp);
return (0);
}
error = ENXIO;
goto bad;
}
error = ENOENT;
for (i = 0; i < nkern_targets; i++) {
struct kern_target *kt = &kern_targets[i];
if (cnp->cn_namelen == strlen(kt->kt_name) &&
bcmp(kt->kt_name, pname, cnp->cn_namelen) == 0) {
error = 0;
break;
}
}
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_lookup: i = %d, error = %d\n", i, error);
#endif
if (error)
goto bad;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_lookup: allocate new vnode\n");
#endif
error = getnewvnode(VT_UFS, dvp->v_mount, kernfs_vnodeop_p, &fvp);
if (error)
goto bad;
MALLOC(fvp->v_data, void *, sizeof(struct kernfs_node), M_TEMP, M_WAITOK);
VTOKERN(fvp)->kf_kt = &kern_targets[i];
fvp->v_type = VTOKERN(fvp)->kf_kt->kt_vtype;
*vpp = fvp;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_lookup: newvp = %x\n", fvp);
#endif
return (0);
bad:;
*vpp = NULL;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_lookup: error = %d\n", error);
#endif
return (error);
}
kernfs_open(ap)
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
/*
* Can always open the root (modulo perms)
*/
if (vp->v_flag & VROOT)
return (0);
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_open, mode = %x, file = %s\n",
ap->a_mode, VTOKERN(vp)->kf_kt->kt_name);
#endif
if ((ap->a_mode & FWRITE) && !(VTOKERN(vp)->kf_kt->kt_rw & VWRITE))
return (EOPNOTSUPP);
return (0);
}
static int
kernfs_access(ap)
struct vop_access_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct ucred *cred = ap->a_cred;
mode_t mode = ap->a_mode;
if (mode & VEXEC) {
if (vp->v_flag & VROOT)
return (0);
return (EACCES);
}
if (cred->cr_uid == 0) {
if ((vp->v_flag & VROOT) == 0) {
struct kern_target *kt = VTOKERN(vp)->kf_kt;
if ((mode & VWRITE) && !(kt->kt_rw & VWRITE))
return (EROFS);
}
return (0);
}
if (mode & VWRITE)
return (EACCES);
return (0);
}
kernfs_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
int error = 0;
char strbuf[KSTRING];
bzero((caddr_t) vap, sizeof(*vap));
vattr_null(vap);
vap->va_uid = 0;
vap->va_gid = 0;
vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
/* vap->va_qsize = 0; */
vap->va_blocksize = DEV_BSIZE;
microtime(&vap->va_atime);
vap->va_mtime = vap->va_atime;
vap->va_ctime = vap->va_ctime;
vap->va_gen = 0;
vap->va_flags = 0;
vap->va_rdev = 0;
/* vap->va_qbytes = 0; */
vap->va_bytes = 0;
if (vp->v_flag & VROOT) {
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_getattr: stat rootdir\n");
#endif
vap->va_type = VDIR;
vap->va_mode = DIR_MODE;
vap->va_nlink = 2;
vap->va_fileid = 2;
vap->va_size = DEV_BSIZE;
} else {
struct kern_target *kt = VTOKERN(vp)->kf_kt;
int nbytes;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_getattr: stat target %s\n", kt->kt_name);
#endif
vap->va_type = kt->kt_vtype;
vap->va_mode = (kt->kt_rw & VWRITE ? WRITE_MODE : READ_MODE);
vap->va_nlink = 1;
vap->va_fileid = 3 + (kt - kern_targets) / sizeof(*kt);
error = kernfs_xread(kt, strbuf, sizeof(strbuf), &nbytes);
vap->va_size = nbytes;
}
vp->v_type = vap->va_type;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_getattr: return error %d\n", error);
#endif
return (error);
}
kernfs_setattr(ap)
struct vop_setattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
/*
* Silently ignore attribute changes.
* This allows for open with truncate to have no
* effect until some data is written. I want to
* do it this way because all writes are atomic.
*/
return (0);
}
static int
kernfs_read(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct kern_target *kt;
char strbuf[KSTRING];
int off = uio->uio_offset;
int len = 0;
char *cp = strbuf;
int error;
if (vp->v_flag & VROOT)
return (0);
kt = VTOKERN(vp)->kf_kt;
#ifdef KERNFS_DIAGNOSTIC
printf("kern_read %s\n", kt->kt_name);
#endif
error = kernfs_xread(kt, strbuf, sizeof(strbuf), &len);
if (error)
return (error);
cp = strbuf + off;
len -= off;
return (uiomove(cp, len, uio));
}
static int
kernfs_write(ap)
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct kern_target *kt;
char strbuf[KSTRING];
int len = uio->uio_resid;
char *cp = strbuf;
int xlen;
int error;
if (vp->v_flag & VROOT)
return (0);
kt = VTOKERN(vp)->kf_kt;
if (uio->uio_offset != 0)
return (EINVAL);
xlen = min(uio->uio_resid, KSTRING-1);
error = uiomove(strbuf, xlen, uio);
if (error)
return (error);
if (uio->uio_resid != 0)
return (EIO);
strbuf[xlen] = '\0';
xlen = strlen(strbuf);
return (kernfs_xwrite(kt, strbuf, xlen));
}
kernfs_readdir(ap)
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
} */ *ap;
{
struct uio *uio = ap->a_uio;
int i;
int error;
i = uio->uio_offset / UIO_MX;
error = 0;
while (uio->uio_resid > 0 && i < nkern_targets) {
struct dirent d;
struct dirent *dp = &d;
struct kern_target *kt = &kern_targets[i];
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_readdir: i = %d\n", i);
#endif
bzero((caddr_t) dp, UIO_MX);
dp->d_namlen = strlen(kt->kt_name);
bcopy(kt->kt_name, dp->d_name, dp->d_namlen+1);
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_readdir: name = %s, len = %d\n",
dp->d_name, dp->d_namlen);
#endif
/*
* Fill in the remaining fields
*/
dp->d_reclen = UIO_MX;
dp->d_fileno = i + 3;
dp->d_type = DT_UNKNOWN; /* XXX */
/*
* And ship to userland
*/
error = uiomove((caddr_t) dp, UIO_MX, uio);
if (error)
break;
i++;
}
uio->uio_offset = i * UIO_MX;
return (error);
}
kernfs_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
/*
* Clear out the v_type field to avoid
* nasty things happening in vgone().
*/
vp->v_type = VNON;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_inactive(%x)\n", vp);
#endif
return (0);
}
kernfs_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_reclaim(%x)\n", vp);
#endif
if (vp->v_data) {
FREE(vp->v_data, M_TEMP);
vp->v_data = 0;
}
return (0);
}
/*
* Print out the contents of a /dev/fd vnode.
*/
/* ARGSUSED */
kernfs_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
printf("tag VT_NON, kernfs vnode\n");
return (0);
}
/*void*/
kernfs_vfree(ap)
struct vop_vfree_args /* {
struct vnode *a_pvp;
ino_t a_ino;
int a_mode;
} */ *ap;
{
return (0);
}
/*
* /dev/fd vnode unsupported operation
*/
kernfs_enotsupp()
{
return (EOPNOTSUPP);
}
/*
* /dev/fd "should never get here" operation
*/
kernfs_badop()
{
panic("kernfs: bad op");
/* NOTREACHED */
}
/*
* kernfs vnode null operation
*/
kernfs_nullop()
{
return (0);
}
#define kernfs_create ((int (*) __P((struct vop_create_args *)))kernfs_enotsupp)
#define kernfs_mknod ((int (*) __P((struct vop_mknod_args *)))kernfs_enotsupp)
#define kernfs_close ((int (*) __P((struct vop_close_args *)))nullop)
#define kernfs_ioctl ((int (*) __P((struct vop_ioctl_args *)))kernfs_enotsupp)
#define kernfs_select ((int (*) __P((struct vop_select_args *)))kernfs_enotsupp)
#define kernfs_mmap ((int (*) __P((struct vop_mmap_args *)))kernfs_enotsupp)
#define kernfs_fsync ((int (*) __P((struct vop_fsync_args *)))nullop)
#define kernfs_seek ((int (*) __P((struct vop_seek_args *)))nullop)
#define kernfs_remove ((int (*) __P((struct vop_remove_args *)))kernfs_enotsupp)
#define kernfs_link ((int (*) __P((struct vop_link_args *)))kernfs_enotsupp)
#define kernfs_rename ((int (*) __P((struct vop_rename_args *)))kernfs_enotsupp)
#define kernfs_mkdir ((int (*) __P((struct vop_mkdir_args *)))kernfs_enotsupp)
#define kernfs_rmdir ((int (*) __P((struct vop_rmdir_args *)))kernfs_enotsupp)
#define kernfs_symlink ((int (*) __P((struct vop_symlink_args *)))kernfs_enotsupp)
#define kernfs_readlink \
((int (*) __P((struct vop_readlink_args *)))kernfs_enotsupp)
#define kernfs_abortop ((int (*) __P((struct vop_abortop_args *)))nullop)
#define kernfs_lock ((int (*) __P((struct vop_lock_args *)))nullop)
#define kernfs_unlock ((int (*) __P((struct vop_unlock_args *)))nullop)
#define kernfs_bmap ((int (*) __P((struct vop_bmap_args *)))kernfs_badop)
#define kernfs_strategy ((int (*) __P((struct vop_strategy_args *)))kernfs_badop)
#define kernfs_islocked ((int (*) __P((struct vop_islocked_args *)))nullop)
#define kernfs_advlock ((int (*) __P((struct vop_advlock_args *)))kernfs_enotsupp)
#define kernfs_blkatoff \
((int (*) __P((struct vop_blkatoff_args *)))kernfs_enotsupp)
#define kernfs_valloc ((int(*) __P(( \
struct vnode *pvp, \
int mode, \
struct ucred *cred, \
struct vnode **vpp))) kernfs_enotsupp)
#define kernfs_truncate \
((int (*) __P((struct vop_truncate_args *)))kernfs_enotsupp)
#define kernfs_update ((int (*) __P((struct vop_update_args *)))kernfs_enotsupp)
#define kernfs_bwrite ((int (*) __P((struct vop_bwrite_args *)))kernfs_enotsupp)
int (**kernfs_vnodeop_p)();
struct vnodeopv_entry_desc kernfs_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_lookup_desc, kernfs_lookup }, /* lookup */
{ &vop_create_desc, kernfs_create }, /* create */
{ &vop_mknod_desc, kernfs_mknod }, /* mknod */
{ &vop_open_desc, kernfs_open }, /* open */
{ &vop_close_desc, kernfs_close }, /* close */
{ &vop_access_desc, kernfs_access }, /* access */
{ &vop_getattr_desc, kernfs_getattr }, /* getattr */
{ &vop_setattr_desc, kernfs_setattr }, /* setattr */
{ &vop_read_desc, kernfs_read }, /* read */
{ &vop_write_desc, kernfs_write }, /* write */
{ &vop_ioctl_desc, kernfs_ioctl }, /* ioctl */
{ &vop_select_desc, kernfs_select }, /* select */
{ &vop_mmap_desc, kernfs_mmap }, /* mmap */
{ &vop_fsync_desc, kernfs_fsync }, /* fsync */
{ &vop_seek_desc, kernfs_seek }, /* seek */
{ &vop_remove_desc, kernfs_remove }, /* remove */
{ &vop_link_desc, kernfs_link }, /* link */
{ &vop_rename_desc, kernfs_rename }, /* rename */
{ &vop_mkdir_desc, kernfs_mkdir }, /* mkdir */
{ &vop_rmdir_desc, kernfs_rmdir }, /* rmdir */
{ &vop_symlink_desc, kernfs_symlink }, /* symlink */
{ &vop_readdir_desc, kernfs_readdir }, /* readdir */
{ &vop_readlink_desc, kernfs_readlink }, /* readlink */
{ &vop_abortop_desc, kernfs_abortop }, /* abortop */
{ &vop_inactive_desc, kernfs_inactive }, /* inactive */
{ &vop_reclaim_desc, kernfs_reclaim }, /* reclaim */
{ &vop_lock_desc, kernfs_lock }, /* lock */
{ &vop_unlock_desc, kernfs_unlock }, /* unlock */
{ &vop_bmap_desc, kernfs_bmap }, /* bmap */
{ &vop_strategy_desc, kernfs_strategy }, /* strategy */
{ &vop_print_desc, kernfs_print }, /* print */
{ &vop_islocked_desc, kernfs_islocked }, /* islocked */
{ &vop_advlock_desc, kernfs_advlock }, /* advlock */
{ &vop_blkatoff_desc, kernfs_blkatoff }, /* blkatoff */
{ &vop_valloc_desc, kernfs_valloc }, /* valloc */
{ &vop_vfree_desc, kernfs_vfree }, /* vfree */
{ &vop_truncate_desc, kernfs_truncate }, /* truncate */
{ &vop_update_desc, kernfs_update }, /* update */
{ &vop_bwrite_desc, kernfs_bwrite }, /* bwrite */
{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
};
struct vnodeopv_desc kernfs_vnodeop_opv_desc =
{ &kernfs_vnodeop_p, kernfs_vnodeop_entries };